删了很多，只留下了主要脉络，以便回忆TOMCAT如何做到多线程处理请求
/**
* The set of processors that have been created but are not currently
* being used to process a request.
*/
private Stack processors = new Stack();
/**
* The set of processors that have ever been created.
*/
private Vector created = new Vector();
/**
* The current number of processors that have been created.
*/
private int curProcessors = 0;
/**
* Create (or allocate) and return an available processor for use in
* processing a specific HTTP request, if possible. If the maximum
* allowed processors have already been created and are in use,
* returnnull instead.
**/
private HttpProcessor createProcessor() {
synchronized (processors) {
if (processors.size() > 0) {
// if (debug >= 2)
// log("createProcessor: Reusing existing processor");
return ((HttpProcessor) processors.pop());
}
if ((maxProcessors > 0) && (curProcessors < maxProcessors)) {
// if (debug >= 2)
// log("createProcessor: Creating new processor");
return (newProcessor());
} else {
if (maxProcessors < 0) {
// if (debug >= 2)
// log("createProcessor: Creating new processor");
return (newProcessor());
} else {
// if (debug >= 2)
// log("createProcessor: Cannot create new processor");
return (null);
}
}
}
}
/**
* Create and return a new processor suitable for processing HTTP
* requests and returning the corresponding responses.
*/
private HttpProcessor newProcessor() {
// if (debug >= 2)
// log("newProcessor: Creating new processor");
HttpProcessor processor = new HttpProcessor(this, curProcessors++);
if (processor instanceof Lifecycle) {
try {
((Lifecycle) processor).start();
} catch (LifecycleException e) {
log("newProcessor", e);
return (null);
}
}
created.addElement(processor);
return (processor);
}
/**
* The background thread that listens for incoming TCP/IP
*connections and
* hands them off to an appropriate processor.
*/
public void run() {
// Loop until we receive a shutdown command
while (!stopped) {
// Accept the next incoming connection from the server socket
Socket socket = null;
try {
// if (debug >= 3)
// log("run: Waiting on serverSocket.accept()");
socket = serverSocket.accept();
// if (debug >= 3)
} catch (Exception e) {
continue;
}
// Hand this socket off to an appropriate processor
HttpProcessor processor = createProcessor();
if (processor == null) {
try {
socket.close();
} catch (IOException e) {
;
}
continue;
}
// if (debug >= 3)
// log("run: Assigning socket to processor " + processor);
processor.assign(socket);
}
}